Searching for the ideal vintage bookshelf speakers.

Honestly, this thread makes me laugh. It's like you're asking "Which old, rare, finicky sports car should I buy to drive only in bumper-to-bumper traffic at 20 mph?" Then all the discussion of the nuanced differences between the Lambo, the Ferrari & the Lotus.

If your criteria includes "speakers will sit horizontally atop two bookcases", your in room performance will be so compromised that the list of 6 issues seems really over the top. You need to setup most monitors on proper stands somewhat away from the wall behind them to get anywhere near their capabilities. 

OP's list of concerns indicates a fairly high bar of what he's hoping to achieve. Perhaps if lifestyle issues preclude proper setup, consider a nice set of headphones instead.  Sorry, not trying to be Debbie Downer, here. Cheers,
Spencer

OK. So you want a pair of 40+ year-old bookshelf speakers, installed high on bookshelves (with 31" vertical clearance) to fill a space almost the size of a 2-car garage, but NO SUBWOOFER.

Well, I think I almost have an answer. It may meet a lot of objections here, but for your purposes it should meet your visual and sonic requirements well.

With that size of a space, I doubt you’re looking for pinpoint imaging. You’d probably like a large soundstage so you have an even balance as you move about your studio.

So here’s my suggestion: Bose 901 direct/reflecting speakers. No need to buy used; they’re still in production and look pretty much as retro as the originals. It also means a factory warranty and all the parts are available and in production.

But for these to work right you’ll need to fudge a little on your placement ideas while not violating the general idea of keeping them up and out of the way. The 901s have eight rear-firing 4.5" drivers and a small port. There has to be at least 12" between the back of the speaker and the wall behind it. Two or three feet might be better. Setting them on the top of your bookshelves leave no space between the back of the speakers and the wall, but you could hang them from the ceiling on cables or chains, at the same height as if they were on top of the bookshelf, and about 1-2 feet in front of the wall behind.

Bring a lot of power to the party--150-250 wpc preferred. They will play a wide variety of music well. They will fill your space pretty effortlessly, and with a high current powerful amp, you’ll have fast, tight bass. You’ll also get a stable soundstage and pretty uniform volume and timbre response throughout your studio.

Tone Publications did this review of the 901s, listening to them without prejudice, and flew in the face of long-running audiophile sentiment with a very favorable review, especially at their asking price of $1395/pair.

Thank you for your replies. Unfortunately, most missed the mark. I like vintage audio equipment in the same way I like vintage automobiles, vintage books, vintage paintings, vintage architecture and vintage furniture. Yes, I am still interested in an intelligent discussion regarding vintage bookshelf speakers. Thank you yakbob, yashu and johnnyb53 for your thoughtful comments. I hope to hear from more people who can address the specifics of my initial post. Best wishes.

unclechoppy, a few thoughts based upon some decades of experience.

First, the term "bookshelf speaker" has an unfortunate evolution.  It is true it connotes speakers of a size and weight that could fit and be supported by a bookshelf.  But very few of them sounded as good there as compared to placement on stands and out away from the walls.  Your 4th point includes imaging and only a few speakers have been designed to image well close to a wall and surrounded by other objects on bookshelves.

Second, with your appreciation of "vintage audio", understand that some repair/updating will be likely.  Many woofers and some mid-range drivers were built with foam surrounds which may not survive even 20 years.  Fortunately surrounds can be replaced.  Crossovers will likely include parts which benefit from upgrading, particularly capacitors.  A number of "vintage" speakers included tone switches with two to five positions.  Those too may require replacement.  Cosmetics are a personal choice but finding 30 year old speakers with good finish on the cabinets and speaker cloth which is not soiled or ripped may not be easy.  Of course they can be restored too.

Third, I've never owned any of the speakers you listed, though I have heard some specifically and others in similar models.  From my experiences I can recommend two choices if you want to pursue this.  The Dynaco A-25 (or rare A-25XL) if deep bass is not too important, and the Large Advent if bass is important.  The A-25 can be driven by smaller amps (20 - 60 wpc) and sound good with either tube or SS of reasonable quality.  The Advent will need more power (50 - 200 wpc).  I've never heard those driven by tubes but something with KT-88, 6550, or the new KT-150 may be fine.  Also, both are 2-way systems, thus easier to restore.

Lastly, the danger in recommending any old/used component is it will depend on what you can find in your price range.  I could suggest you get the Blast-off X 1000 but while looking for that you might miss the QRD which would be just as good or better.  Therefore, having a list of candidates rather than one specific model will be best.  And allow some $ out of your budget for restorations mentioned above, just like that vintage auto.

Good luck, and let us know what you find.

Your requested specifics on Spendor SP1:

1.  Thin walls but solid.  Fine workmanship.  Mine still look great.
2.  Extremely natural realistic presentation.  Vocals are marvelous.
3.  No brightness.  Leans towards warm, musical with sufficient detail.
4.  Wide open soundstage - however you can pinpoint specific instruments in small combos, etc.
5.  No listener fatigue.  I listen for hours to all types is music.
6.  I always used a SS amp.  Have heard they work well with tubes.

Hope this helps